Radiolysis of Amino Acids in Outer Solar-System Ice Analogs
Amino acids have been found in cometary dust particles and in the
organic component of meteorites. These molecules, important for
pre-biotic chemistry and for active biological systems, might be formed
in cold planetary or interstellar environments and then delivered to
H2O-rich surfaces in the outer Solar System. Many models for the
availability of organic species on Earth and elsewhere depend on the
ability of these molecules to survive in radiation-rich space
environments. This poster presents results of 0.8-MeV proton radiolysis
of ice films at 15-140K. Using infrared spectroscopy, the destruction
rates of glycine, alanine, and phenylalanine have been determined for
both pure films and those containing amino acids diluted in H2O. Our
results are discussed in terms of the survivability of these molecules
in the icy surfaces present in the outer Solar System and the
possibility of their detection by instruments on board the New Horizons
spacecraft.